EP0043576A1 - Molybdänlegierung - Google Patents

Molybdänlegierung Download PDF

Info

Publication number
EP0043576A1
EP0043576A1 EP81105240A EP81105240A EP0043576A1 EP 0043576 A1 EP0043576 A1 EP 0043576A1 EP 81105240 A EP81105240 A EP 81105240A EP 81105240 A EP81105240 A EP 81105240A EP 0043576 A1 EP0043576 A1 EP 0043576A1
Authority
EP
European Patent Office
Prior art keywords
molybdenum
alloy
scandium
present
ingot
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP81105240A
Other languages
English (en)
French (fr)
Other versions
EP0043576B1 (de
Inventor
Shotaro Morozumi
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
MOROZUMI, SHOTARO
Toshiba Corp
Original Assignee
Toshiba Corp
Tokyo Shibaura Electric Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Toshiba Corp, Tokyo Shibaura Electric Co Ltd filed Critical Toshiba Corp
Priority to AT81105240T priority Critical patent/ATE7155T1/de
Publication of EP0043576A1 publication Critical patent/EP0043576A1/de
Application granted granted Critical
Publication of EP0043576B1 publication Critical patent/EP0043576B1/de
Expired legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C27/00—Alloys based on rhenium or a refractory metal not mentioned in groups C22C14/00 or C22C16/00
    • C22C27/04—Alloys based on tungsten or molybdenum

Definitions

  • the present invention relates to a molybdenum-based alloy and, more particularly, to a molybdenum-based alloy with excellent workability.
  • Molybdenum is known to have excellent resistance against high temperatures and is used for heat-resistant structural parts or as lamp bulb materials.
  • molybdenum as cast has a relatively high ductile-brittle transition temperature and poor ductility, and requires working at high temperatures such as 1,400°C.
  • the transition temperature of molybdenum can be lowered by working such as forging, it is only lowered slightly, resulting in the requirement of high temperatures for working.
  • the amount of Re to be added is as large as 20 to 50%. Addition of Re in such a large amount indicates that the addition of Re to Mo is intended to change the essential properties of the alloy. It is further known that the addition of Th in an amount of about 10% lowers by a maximum of 100°C the ductile-brittle transition temperature of molybdenum after casting without further processing (i.e., as cast). It is also known that the addition of elements, other than Re and Th, in amounts of 0.005 to 1.0% provide similar effects as the addition of Th.
  • the other principle aims at lowering the temperature for hot working of molybdenum or a molybdenum-based alloy.
  • the primary object of the present invention to provide a molybdenum-based alloy which exhibits excellent workability at relatively low temperatures.
  • the present invention provides a molybdenum-based alloy consisting essentially of 0.001 to 0.5% by weight of scandium with the remainder being essentially molybdenum.
  • molybdenum generally exhibits poor workability, and cracks form mainly at the grain boundaries during hot working.
  • the formation of these cracks is considered to be mainly attributable to precipitation or segregation of impurities present in small amounts, especially oxides or carbides.
  • the crystal grains are extremely coarse, so that the above-mentioned impurities may significantly exert an influence on intergranular embrittlement.
  • Scandium which is added to molybdenum according to the present invention shows a strong deoxidation tendency and thus especially reduces oxides among the impurities which precipitate or segregate into the grain boundaries.
  • the molybdenum-based alloy of the present invention does not exhibit intergranular embrittlement even at relatively low temperatures and thus allows various types of working such as forging, rolling, swaging, and drawing in an excellent manner (i.e., working is easy and cracks do not form) at relatively low temperatures (e.g., 800°C or less).
  • relatively low temperatures e.g. 800°C or less.
  • the molybdenum-based alloy of the present invention exhibits low reduction in strength and hardness and even better elongation at high temperatures. As a result, the alloy of the present invention has excellent resistance to stress.
  • the molybdenum-based alloy of the present invention may also contain Co, Cr, Fe, Re, Ru, V, Nb, Ti, W, Zr, B and the like.
  • the present inventors have made extensive studies for the purpose of improving the workability at relatively low temperatures of molybdenum as cast. In order to reduce especially the oxides among the impurities which precipitate or segregate into the grain boundaries of Mo, various elements were added to molybdenum and the workability of the resultant molybdenum-based alloys at relatively low temperatures was examined. As a result of these studies, it has been found that scandium has strong affinity for oxygen and that the addition of scandium largely improves the workability of the molybdenum-based alloy, thus establishing the present invention.
  • the molydenum-based alloy of the present invention contains 0.001 to 0.5% by weight of scandium.
  • scandium content deviates from this range, cracks tend to form during working at relatively low temperatures (e.g., 800°C).
  • the remaining portion of the alloy of the present invention consists essentially of molybdenum.
  • molybdenum as a raw material generally unavoidably contains impurities such as carbon, oxygen, nitrogen and so on.
  • the impurity contents in the alloy of the present invention are preferably no more than 0.025% for C, no more than 0.0015% for O, and no more- than 0.0010% for N.
  • Impurities other than those specified above, such as Ca, Mg, Ni and Cu, are preferably contained in the alloy in as small amounts as possible.
  • the improving effects of workability obtained with scandium may still be obtained with a molybdenum containing 1% or less of Co and Fe; 30% or less of Re; 0.5% or less of Ru; 10% or less of V, Nb, Cr and Ti; 50% or less of W; and 0.5% or less of Zr and/or 0.001 to 0.1% of B.
  • Molybdenum as a principal raw material of the alloy of the present invention may be a commercially available powder of pure molybdenum, and preferably contains the smallest possible amounts of C, O and N, as described above.
  • the scandium raw material to be added to the alloy of the present invention may be a metal scandium powder or a scandium compound such as a scandium hydride, a scandium halogenide, a scandium hydroxide, a scandium boride, a.scandium carbide, or a scandium intermetallic compound such as Sc-V.
  • a scandium hydride which may be available at relatively inexpensive cost in powder form and which contains hydrogen having a strong tendency for reduction.
  • the above-mentioned molybdenum powder and the scandium-containing raw material powder are well mixed together with the other alloy components or elements mentioned above, if desired, and pressed to provide a green compact which is then melted in a non-oxidizing atmosphere.
  • the melting may be performed in an arc furnace having non-consumable or consumable type electrodes, or it may be performed by heating with an electron beam or a plasma arc. It is preferable to maintain the mixture in the molten state for a sufficient time to allow scandium and oxygen to react fully.
  • the resultant slag is removed from the molten mass which is then cast to provide an ingot of the molybdenum-based alloy of the present invention.
  • the amount of the scandium-containing raw material to be used must be sufficient (e.g., the amount that added scandium accounts for 0.1 to 1.0% by weight) so that the scandium content in the resultant alloy is 0.001 to 0.5%.
  • the amount of the scandium-based raw material to be added differs depending upon the amount of oxygen contained in the molybdenum, it may be easily determined by performing a preliminary test.
  • the content of the remaining scandium is preferably 0.2% or less.
  • the alloy of the present invention may be generally prepared by the melting method as described above, it may alternatively be prepared by sintering the green compact described above to provide a sintered ingot.
  • the workability is better and cracks do not form during forging or rolling at relatively low temperatures such as 800°C, unlike the ingot or sintered ingot of the prior art molybdenum-based alloys.
  • the rate of decrease in the ductile-brittle transition temperature in forging is also great with the alloy of the present invention and shows, for example, a transition temperature around room temperature at a 50% draft.
  • top and bottom surfaces of these 8 different kinds of ingots were ground to provide plates of about 8 mm thickness. They were then forged to a thickness of 3 mm at temperatures between 400 and 1,000°C in increments of 100°C. They were then rolled at the respective temperatures to provide plates of 1 mm thickness.
  • samples No. 1 and 2 As a result, cracks formed at the respective temperatures in samples No. 1 and 2, that is, the sample with no scandium added and the sample with 0.05% added scandium and less than 0.001% remaining.
  • samples No. 2 to 8 provided excellent working samples in which cracks did not form at all at the temperatures tested. It follows from this that addition of scandium contributes to improving the workability of molybdenum. It has also been found that when the remaining scandium content exceeded 0.5%, cracks tended to form unless the lowest working temperature was elevated. Marks o and x in Table 1 respectively indicate excellent and poor workability of the samples obtained.
  • a 99.90% pure Mo powder was treated in wet hydrogen at 900°C. After adding a scandium hydride powder to the Mo powder, the mixture was mixed well in a V-type mixer for 2 hours. The mixture was arc-melted with non-consumable type tungsten electrodes in an argon atmosphere to provide an ingot of 30 mm thickness, 30 mm width, and 70 mm length. This ingot was forged within a temperature range of 700 to 1,300°C to reduce the thickness from 30 mm to 11 mm at the first step and then from 11 mm to 5 mm at the second step. Next, the ingot was hot-worked at a draft of 74% within a temperature range of 700 to 1,300°C to reduce the thickness from 5 mm to 1.3 mm. Thereafter, the ingot was held at 900°C for 20 minutes and was annealed. The annealed ingot was then cold-worked at a draft of 75% to reduce the thickness from 1.3 mm to 0.33 mm.
  • Fig. 1 shows the relationship between the annealing temperature and the tensile strength or elongation of the samples.
  • curves (a) and (b) correspond to the alloy of the present invention and show the relationship between the annealing temperature and the tensile strength and between the annealing temperature and the elongation of a sample having a 0.034% remaining scandium content.
  • Curves (c) and (d) show the relationship between the annealing temperature and the tensile strength and between the annealing temperature and the elongation for a sample obtained by similarly hot working, annealing, and cold working a molybdenum sintered body for electric appliances (99.90% or higher in purity), as defined by JIS H 4483.
  • the annealing temperature when the annealing temperature is higher, the elongation of the alloy of the present invention becomes greater while the elongation of the commercially available pure molybdenum is decreased at temperatures above 1,100°C. It is seen from this that the alloy of the present invention is stable in strength at high temperatures. Therefore, the alloy of the present invention exhibits better resistance than the commercially available pure molybdenum upon being repeatedly subjected to stress at high temperatures.
  • Fig. 2 The relations between the annealing temperature and hardness (Hv) of the samples of the alloy of the present invention and the commercially available pure molybdenum (JIS H 4483) are shown in Fig. 2.
  • curve (e) corresponds to an alloy of the present invention.
  • Marks o represent the relationship between the hardness (Hv) and the annealing temperature for the side face along the direction of rolling of the sample in the final cold working
  • marks 0 represent the relationship between the hardness (Hv) and the annealing temperature for the end face of the sample along the direction of rolling.
  • Curve (f) corresponds to a commercially avilable molybdenum.
  • the hardness of the alloy of the present invention is far greater than that of the prior art molybdenum at the same annealing temperature.
  • the alloy of the present invention although work-hardened, exhibits excellent workability as compared with the prior art pure molybdenum.
  • Molybdenum-based alloys of the compositions as shown in Table 2 were prepared according to the same procedures of Example 1, and the forgeability and rollability of these alloys were examined. The obtained results are shown in Table 2 wherein mark o indicates an evaluation of excellent, mark ⁇ indicates good, and mark x indicates poor.
  • the workability at relatively low temperatures is improved with the alloys of the present invention since the addition of scandium results in sufficient deoxidation and therefore a reduction in precipitation of oxides or the like in the grain boundaries. It is further considered that the addition of scandium not only contributes to deoxidation but also to improving other properties such as workability, tensile strength, elongation and hardness (Hv) of the alloy of the present invention, although the reasons for this remain unknown.
  • lamp bulb parts may be conveniently manufactured from plates of the alloy of the present invention and wires may also be manufactured. Further, considering the tendency of the tensile strength, elongation and hardness to change upon annealing, the mechanical strength of the heat-resistant members using molybdenum plates may be improved by the use of the alloy of the present invention. Finally embrittlement of prior art molybdenum material upon irradiation by neutrons for nuclear power may be significantly reduced by using the alloy material of the present invention.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Manufacture And Refinement Of Metals (AREA)
  • Solid Thermionic Cathode (AREA)
  • Powder Metallurgy (AREA)
  • Pistons, Piston Rings, And Cylinders (AREA)
EP81105240A 1980-07-08 1981-07-06 Molybdänlegierung Expired EP0043576B1 (de)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT81105240T ATE7155T1 (de) 1980-07-08 1981-07-06 Molybdaenlegierung.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP55092198A JPS5853703B2 (ja) 1980-07-08 1980-07-08 熱間加工性に優れたモリブデン材料
JP92198/80 1980-07-08

Publications (2)

Publication Number Publication Date
EP0043576A1 true EP0043576A1 (de) 1982-01-13
EP0043576B1 EP0043576B1 (de) 1984-04-18

Family

ID=14047742

Family Applications (1)

Application Number Title Priority Date Filing Date
EP81105240A Expired EP0043576B1 (de) 1980-07-08 1981-07-06 Molybdänlegierung

Country Status (5)

Country Link
US (1) US4370299A (de)
EP (1) EP0043576B1 (de)
JP (1) JPS5853703B2 (de)
AT (1) ATE7155T1 (de)
DE (1) DE3163202D1 (de)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5028756A (en) * 1988-10-18 1991-07-02 Sumitomo Electric Industries, Ltd. Electrode wire for electric spark cutting
AT15903U1 (de) * 2017-09-29 2018-08-15 Plansee Se Molybdän-Sinterteil

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AT377584B (de) 1981-06-25 1985-04-10 Klima & Kaelte Gmbh Eck-verbindung an metallrahmen
US4755712A (en) * 1986-12-09 1988-07-05 North American Philips Corp. Molybdenum base alloy and lead-in wire made therefrom
DE4442161C1 (de) * 1994-11-27 1996-03-07 Bayerische Metallwerke Gmbh Verfahren zur Herstellung eines Formteils
JPH08165528A (ja) * 1994-12-09 1996-06-25 Japan Energy Corp 高純度高融点金属または合金の製造方法
DE102005003445B4 (de) * 2005-01-21 2009-06-04 H.C. Starck Hermsdorf Gmbh Metallsubstrat-Werkstoff für die Anodenteller von Drehanodenröntgenröhren, Verfahren zur Herstellung eines solchen Werkstoffes sowie Verfahren zur Herstellung eines Anodentellers unter Verwendung eines solchen Werkstoffes
EP2027964B1 (de) * 2006-06-08 2015-07-22 Nippon Tungsten Co., Ltd. Elektrode für punktschweissen

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2883284A (en) * 1956-07-30 1959-04-21 Westinghouse Electric Corp Molybdenum base alloys
GB941945A (en) * 1960-05-23 1963-11-20 American Metal Climax Inc Molybdenum and/or tungsten base alloy castings and methods of making such cast alloys
CH394624A (de) * 1960-04-11 1965-06-30 Stauffer Chemical Co Verfahren zur Herstellung von feinkörnigem metallischem Wolfram oder Molybdän
GB1049957A (en) * 1964-09-11 1966-11-30 Atomic Energy Commission Blazing alloys for tungsten and molybdenum
US3841846A (en) * 1970-01-25 1974-10-15 Mallory & Co Inc P R Liquid phase sintered molybdenum base alloys having additives and shaping members made therefrom

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2188405A (en) * 1939-02-11 1940-01-30 Mallory & Co Inc P R Molybdenum alloys
US2678269A (en) * 1951-10-06 1954-05-11 Climax Molybdenum Co Molybdenum-titanium alloys
US2678268A (en) * 1951-10-06 1954-05-11 Climax Molybdenum Co Molybdenum-vanadium alloys
US2678272A (en) * 1951-10-06 1954-05-11 Climax Molybdenum Co Molybdenum-columbium alloys
US2883283A (en) * 1957-07-02 1959-04-21 Horizons Inc Oxidation resistant molybdenum base alloy

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2883284A (en) * 1956-07-30 1959-04-21 Westinghouse Electric Corp Molybdenum base alloys
CH394624A (de) * 1960-04-11 1965-06-30 Stauffer Chemical Co Verfahren zur Herstellung von feinkörnigem metallischem Wolfram oder Molybdän
GB941945A (en) * 1960-05-23 1963-11-20 American Metal Climax Inc Molybdenum and/or tungsten base alloy castings and methods of making such cast alloys
GB1049957A (en) * 1964-09-11 1966-11-30 Atomic Energy Commission Blazing alloys for tungsten and molybdenum
US3841846A (en) * 1970-01-25 1974-10-15 Mallory & Co Inc P R Liquid phase sintered molybdenum base alloys having additives and shaping members made therefrom

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
High temperature Materials, Conference Held in Cleveland, Ohio, April 16-17, 1957 Edited by R.F. HEHEMANN et al. John Wiley & Sons, Inc. New York (US) J.J. HARWOOD et al.: "Molybdenum, its Alloys and its Protection" pages 243-272 *
Journal of the Less-Common Metals, Vol. 7, 1964 (US) A.D. ZUMBRUNNEN: "Grain Refinement and Improved Ductility in Molybdenum by Small Boron Additions" pages 356,356 *
Journal of the Less-Common Metals, Vol. 9, 1965 (US) A. TAYLOR et al.: "Solid Solubility Limits of Y and Sc in the Elements W,Ta,Mo,Nb, and Cr" pages 214-232 *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5028756A (en) * 1988-10-18 1991-07-02 Sumitomo Electric Industries, Ltd. Electrode wire for electric spark cutting
AT15903U1 (de) * 2017-09-29 2018-08-15 Plansee Se Molybdän-Sinterteil
US11925984B2 (en) 2017-09-29 2024-03-12 Plansee Se Sintered molybdenum part

Also Published As

Publication number Publication date
US4370299A (en) 1983-01-25
JPS5719352A (en) 1982-02-01
DE3163202D1 (en) 1984-05-24
EP0043576B1 (de) 1984-04-18
ATE7155T1 (de) 1984-05-15
JPS5853703B2 (ja) 1983-11-30

Similar Documents

Publication Publication Date Title
EP0304181B1 (de) Schwermetallegierungen aus Wolfram-Nickel-Eisen-Kobalt mit hoher Härte und Verfahren zur Herstellung dieser Legierungen
EP1340825B1 (de) Nickelbasislegierung, heissbeständige Feder aus dieser Legierung und Verfahren zur Herstellung dieser Feder
US3767385A (en) Cobalt-base alloys
CA1066922A (en) Heat-resistant allow for welded structures
US4386976A (en) Dispersion-strengthened nickel-base alloy
EP3572541B1 (de) Superlegierung auf nickelbasis
EP1652945B1 (de) Feinkörniges, rekristallisiertes, Silizium enthaltendes Niob- oder Tantal-Blech, das durch Schmelzen gefolgt von einem thermo-mechanischen Prozess hergestellt wird
US4370299A (en) Molybdenum-based alloy
EP0593824A1 (de) Monokristalline Nickelaluminid-Basis-Legierungen und Verfahren
US4165982A (en) Molybdenum base alloy having excellent high-temperature strength and a method of producing same
US3268328A (en) Metallurgy
US3156560A (en) Ductile niobium and tantalum alloys
US3317314A (en) Columbium-base alloy
Morito Effect of impurities on the weldability of powder metallurgy, electron-beam melted and arc-melted molybdenum and its alloys
US2883284A (en) Molybdenum base alloys
Seagle et al. Electron-Beam Melting: Does It Improve the Properties of Metals and Compounds?
US3193661A (en) Welding rod and electrode
JPH06279894A (ja) 強度および導電性に優れた銅合金
Liu et al. Preparation of ductile nickel aluminides for high temperature use
US3753703A (en) Sintered molybdenum boron alloy
US4448606A (en) Molybdenum-tungsten based alloys containing hafnium carbide
USRE26122E (en) Ductile niobium and tantalum alloys
KR102509526B1 (ko) 바나듐 석출물을 포함하는 석출경화형 고 엔트로피 합금
JPH06271901A (ja) 焼結性に優れたＴｉ−Ａｌ系金属間化合物粉末およびその焼結体
JPH0215618B2 (de)

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19810708

AK Designated contracting states

Designated state(s): AT DE FR GB IT NL

ITF It: translation for a ep patent filed
GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Designated state(s): AT DE FR GB IT NL

REF Corresponds to:

Ref document number: 7155

Country of ref document: AT

Date of ref document: 19840515

Kind code of ref document: T

REF Corresponds to:

Ref document number: 3163202

Country of ref document: DE

Date of ref document: 19840524

ET Fr: translation filed
RAP2 Party data changed (patent owner data changed or rights of a patent transferred)

Owner name: MOROZUMI, SHOTARO

Owner name: KABUSHIKI KAISHA TOSHIBA

REG Reference to a national code

Ref country code: FR

Ref legal event code: CD

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
REG Reference to a national code

Ref country code: GB

Ref legal event code: 746

ITTA It: last paid annual fee
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 19950626

Year of fee payment: 15

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 19950710

Year of fee payment: 15

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 19950711

Year of fee payment: 15

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: AT

Payment date: 19950713

Year of fee payment: 15

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NL

Payment date: 19950727

Year of fee payment: 15

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Effective date: 19960706

Ref country code: AT

Effective date: 19960706

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Effective date: 19970201

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 19960706

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Effective date: 19970328

NLV4 Nl: lapsed or anulled due to non-payment of the annual fee

Effective date: 19970201

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Effective date: 19970402

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST